Shows the effect of regex caching in python.

caching.py

from re import _MAXCACHE, _cache
from timeit import timeit

setup = '''
from re import compile

def create_regex(n):
	return compile(r'^(a*b*|a+c*|b*|c*)a*b*c*(a*|(b*|c*)){:03}$'.format(n))

def run(n):
	for i in xrange(n):
		create_regex(i)
'''

for n in xrange(_MAXCACHE + 10):
	_cache.clear()
	t = timeit('run({})'.format(n), setup, number = 10)
	print "{}\t{}".format(n, t)